SEOUL >> The powerful sister of North Korean leader Kim Jong Un alleged on Monday that the country’s warplanes repelled a U.S. spy plane that flew over its exclusive economic zone and warned of “shocking” consequences if the U.S. continues reconnaissance activities in the area.

The U.S. and South Korean militaries did not immediately respond to the comments by Kim Yo Jong, one of her brother’s top foreign policy officials, which were published in state media Monday evening.

Earlier Monday, North Korea’s Defense Ministry issued a statement accusing the U.S. of flying spy planes into its “inviolable airspace” and warning that approaching aircraft might be shot down.

South Korea’s Joint Chiefs of Staff responded by denying that the U.S. had flown spy planes into North Korean territory. Spokesperson Lee Sung Joon said at a briefing that the U.S. was conducting standard reconnaissance activities in coordination with South Korea’s military.

Apparently in response to that comment, Kim accused the Joint Chiefs of Staff of acting like a “spokesperson” for the U.S. military and said the U.S. has been intensifying its reconnaissance activities in a serious infringement of North Korea’s sovereignty and safety.

But while the North Korean Defense Ministry statement seemed to imply an intrusion into the country’s territorial airspace, Kim accused the U.S. of sending spy planes over the North’s exclusive economic zone, the area within 200 nautical miles of its territory where it controls rights to natural resources.

Kim said a U.S. spy plane crossed the eastern sea boundary between the Koreas at around 5 a.m. Monday and conducted reconnaissance activities over the North’s exclusive economic zone before being chased away by North Korean warplanes. She said the U.S. aircraft crossed the eastern sea boundary again at around 8:50 a.m., prompting North Korea’s military to issue an unspecified “strong warning” toward the United States.

She said North Korea would take decisive action if the U.S. continues to fly reconnaissance planes over her country’s exclusive economic zone, but added that it would “not take a direct counteraction” for U.S. reconnaissance activities outside of the zone.

“A shocking incident would occur in the long run in the 20-40 kilometer section in which the U.S. spy planes habitually intrude into the sky above the economic water zone” of North Korea, she said.

Kim’s comments come at a time of heightened tensions on the Korean Peninsula as the pace of North Korean weapon tests and U.S.-South Korea joint military exercises have intensified. North Korea has test-fired nearly 100 missiles since the start of 2022 as Kim Jong Un expands a nuclear arsenal he apparently sees as his strongest guarantee of survival.